EEG systems use electrodes connected to a scalp in order to detect small electrical signals. These small signals are generally amplified for further processing. Previous electrodes have utilized differential amplifiers for amplifying the desired signals. However, differential amplifiers require delicate balancing of the resistors used to achieve accurate differential amplification required to achieve a high common mode rejection ratio (CMR) of the system. Standard implementations, even those using delicately-balanced laser trimmed resistors, suffer from the inability to remain perfectly balanced over time and over varying operating conditions.